Effect of CuBr₂salt treatment on the performance of nanocolloidal PPy:PSS multilayer thin film counter electrodes of dye‐sensitized solar cells

Abstract

A thin Pt layer on fluorine-doped tin oxide (FTO) glass is commonly used as the counter electrode (CE) for dyesensitized solar cells (DSCs). We have investigated thin layers on FTO glass made from spherical polypyrrole (PPy)-poly(styrene sulfonate) (PSS) nanocolloidal particles with and without treatment of CuBr 2 and used them as CEs. The colloidal polymer composite (PPy:PSS) was spin-coated at 4000 rpm, and PPy:PSS multilayer (one, three, five) films were employed as the CEs. Aqueous solutions of CuBr 2 (0.5 M and 1 M) were coated onto the multilayer CEs, which increased the efficiency of DSCs. When compared with the untreated PPy:PSS counter electrodes, the CuBr 2 -treated PPy:PSS films showed lower charge-transfer resistance, higher surface roughness, and improved catalytic performance for the reduction of I 2 3 . The enhanced catalytic performance is attributed to the interaction of the superior electrocatalytic activity of PPy:PSS and CuBr 2 salt. Under standard AM 1.5 sunlight illumination, the counter electrodes based on a single-layer PPy:PSS composite with 0.5 M and 1 M CuBr 2 salt treatment demonstrated power conversion efficiencies (PCE) of 5.8% and 5.6%, respectively. These values are significantly higher than that of the untreated PPy:PSS CE and are comparable with that of a Pt CE.

Flexible freestanding conductive nanopaper based on PPy:PSS nanocellulose composite for supercapacitors with high performance

“…The doping state of PPy was confirmed by the peaks at 1170 and 960 cm −1 . The absorption peak at 1033 cm −1 was due to the sulfur dioxide (SO 2 ) group stretching vibrations[14,15,24]. For PPy:PSS/CNP, the FTIR spectra retained the typical characteristic peaks of PPy: PSS and the cellulose peaks almost disappeared, indicating the PPy:PSS was homogeneously coated on the surface of CNFs.…”